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no difference

Thread Status: Hello , There was no answer in this thread for more than 60 days.
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firefly

New Member
Mar 2, 2005
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hello

i recently bought my first freediving fins (cressi gara 2000 ld) and went to the pool. i managed to dive 50m quite easily. but i also dive 50m without fins quite easily. i was thinking that with those big fins itwould be firther. can anyone explain this?? am i doing something wrong??

thanks

sandra
 

Apnea_Addict

Well-Known Member
Nov 27, 2004
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Hi Sandra,

I have heard that you actually burn up the same amount of oxygen for a length of diving with or without fins. I personally think that only applies if one´s swimming style without fins is so perfect that you can glide (mine isn´t). So consider youself lucky ;-) And I think you will get further with more practice and being more used to the long fins.

have fun !

Holger
 

immerlustig

BlueSkunk
Aug 17, 2002
597
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hi

no need to worry!
my guess would be that your fin swimming technique is not as developed as your swimming. in case you have some experience with snorkel or scuba fins you will find that your kicking technique for freediving fins will need some adjustments. you'll find threads here on that topic. a quick tip would be to try slow and wide kicks and take it from there.

enjoy

roland
 

naiad

Apnea Carp
Supporter
Oct 11, 2003
2,897
449
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Hi Sandra,

I also find that there is not much difference in my distance with and without fins. My PBs are 40m with fins and over 33m without. My swimming technique without fins isn't very good, and I think if I improve it then my distance will be much better.

Using fins takes practice, so it should be possible to do a better distance soon. It is very important to have a buddy with you, especially if you are going to push the limits.

Lucia
 

firefly

New Member
Mar 2, 2005
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hi all
thanks for the encouragement, that's very nice ! :thankyou
i was in the pool yesterday again and tried rolands suggestion. it was already getting a bit better. thanks for this idea. i could do the turn and another 10m or so with the same effort as the first time i tried. so maybe i'm not a hopeless case :duh but i have to say the turn with the fins is quite akward.

lucia, i'm not sure yet what it means to push the limit. i am a bit exhausted at the end, but feel rether good. i go to the pool with some friends, so there is someone there, but honestly i wouldn't know what to expect. i already found some threads on the shallow water blackout but it's all a bit confusing ??? but, yes, i try to take it really easy. i find hust so cool to swim with these long fins!!!

greetings to you all, sandra
 

naiad

Apnea Carp
Supporter
Oct 11, 2003
2,897
449
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firefly said:
lucia, i'm not sure yet what it means to push the limit. i am a bit exhausted at the end, but feel rether good. i go to the pool with some friends, so there is someone there, but honestly i wouldn't know what to expect. i already found some threads on the shallow water blackout but it's all a bit confusing ??? but, yes, i try to take it really easy.
I'm glad to hear that you have some friends with you. It is important that they know what you are doing and how to help if there is a problem. If you are going to go for a long distance, make sure that they know about it so that one of them can wait for you on the surface.

I will try to explain better if you have any questions.

Lucia
 

mark gooding

New Member
Feb 16, 2005
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hello,
like yourself im still quite new to freediving. i did an AIDA course not so long ago, it was really good, learnt loads from it, especially good in that there was someone there to point out the mistakes i was making, especially with the fins. found my technique has improved a lot since.
take it easy
 

firefly

New Member
Mar 2, 2005
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hi mark

yes, that might be a good thing to do. i still save money for a trip and then i will go somewhere warm. and maybe find some freedivers. that would be great.

sandra
 

firefly

New Member
Mar 2, 2005
21
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hi

just to let you know about some progress i made. i dived around 75m (1 1/2 laps) with the fins yesterday. i have to say that practising on technique did help a lot. and i also tried the underwater breaststroke again just for comparison and managed only 60m. so i think the fins are making a diffeence.

sandra
 
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gnusa

New Member
Apr 26, 2005
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I think that your swiming tehnique with fins is not at a good level. Yes you probuably are a great swimer but the freediving fins are litle diferent. So just keep on practising with them and tell us how was it.
 

firefly

New Member
Mar 2, 2005
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yes, i keep practising.
since nobody here is a finswimmer it is difficult to find advice. i try to apply some principles of swimming technique in the meantime and some tips i get from reading posts here.
it is very exciting everytime i go into the water. there is always some new discovery.

greetings

sandra

ps and if i'm lucky i'll get a vacation soon :p
 

cjborgert

Well-Known Member
Jul 29, 2001
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Re: no difference: Efficiency vs. Power

One of the great advantages of long blades is that you have the power to get yourself moving back toward the surface when you are at a depth where your body is very negatively bouyant. . .efficiency won't get you moving toward the air, but power will, and the long blades provide power when it is needed.

None of this is to take away from what others have said regarding technique . . .that's important too, especially for increased efficiency.
 

firefly

New Member
Mar 2, 2005
21
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hi cjb

are you suggesting that i should maybe kick harder? doesn't that waste more oxygen?

it sounds interesting and i will try it in the pool today.

thanks

sandra
 

SanSan

New Member
Apr 22, 2005
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hi firefly

I don't think that kicking wery hard in the pool will get U any further. What CJB ment is that U need the power of long fins at greather depths when U'r negative bouyant and have to kick hard to start moving up.
In the poll I swim rather slow about 1m/s or a bit more and most of my friedns do to. Only a few of them like a faster style but U should decide for ur self whats best for U. Its realy not that hard to determine that. Just try it and U will know it.
About ur DNF performance close to ur DYN performance I also agree that style is the most important thing but would add the factor of local muscle build up. I have a friend who regulary makes more in DNF than DYN. He says that in DYN his legs hurt so much that he has to stop swiming although he has air left. In DNF thats not the case so he makes about 5m more :).
I say he has to swim more whith his fins on, make workout for legs... aerobic fist to grow muscles and then start whit anaerobic workout and long sprints under water for anaerobic adaptation. I belive this should help such cases but its a rather long way to go...
 

subaquaticus

Fond of the Red Sea
Oct 10, 2004
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firefly said:
hi cjb

are you suggesting that i should maybe kick harder? doesn't that waste more oxygen?

it sounds interesting and i will try it in the pool today.

thanks

sandra

Maybe your fins are too stiff...

the GARA 2000 (especially the 2000 HF) are designed for deep diving... you need stiff fins to "extract" yourself from the depth (and also to a lesser extent from the surface) ;

for dynamic apnea, it is better to have more supple fins...

try first with normal rubber fins and see what it gets...
 

cjborgert

Well-Known Member
Jul 29, 2001
401
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Don't Kick Harder!

No, No, No. . . sorry that I gave an ambiguous suggestion . . .my comment was meant to explain that there are other reasons to freedive with long blade fins other than purely for efficiency.

When freediving, you don't have a BCD, and so you become very negatively buoyant at depth. It is frustrating, and even a little frightening, to be at 60 or 70 or 100 feet, start to head back up, and find you have to kick like a maniac to get yourself moving toward the surface. . .that feeling of kicking rapidly and going nowhere.

Long blade fins have a larger surface area relative to other fins, and they displace more water with each kick and you will begin to move yourself toward the surface with a couple of firm kicks. Thus, long blades are not necessarily more efficient than other fins, because those couple of big kicks with a long blade take more energy than a couple of kicks with other fins, but you start moving!!

Now, at dynamic apnea depths, negative buoyancy is not the issue, but speed is . . .and long blades can increase your speed more rapidly than other fins . . .by displacing more water with each kick. . .but you pay a great price for speed because of the tremendous increase in resistance as speed increases . . .if I recall correctly, in water, resistance increases as the cube of the velocity. So dynamic apnea requires finding that fine line between efficiency of movement, speed of swimming, streamlining, and oxygen utilization. It is more complex than just how fast or slow you kick.

-Hope that makes more sense.
 
Last edited:

subaquaticus

Fond of the Red Sea
Oct 10, 2004
557
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Re: Don't Kick Harder!

cjborgert said:
No, No, No. . . sorry that I gave an ambiguous suggestion . . .my comment was meant to explain that there are other reasons to freedive with long blade fins other than purely for efficiency.
"efficiency" can be an ambiguous word and requires to be defined... it depends on the goal...

in static apnea "efficiency" is the time you spent underwater...

in dynamic apnea "efficiency" is the length you swim underwater (and not the time)

cjborgert said:
Now, at dynamic apnea depths, negative buoyancy is not the issue, but speed is . . .
this not at all obvious !!! the target in dynamic apnea is not the speed, but the length...

the winner is not the first arrived, but the one who swims the longest distance underwater, disregarding of the time spent...

on the 12th of March, I could admire Stephane Mifsud doing 175 m in dynamic apnea ; he had bi-fins and it took him as long as 3'44" (approx. 30"per 25 m), which was very slow...

with a monofin, you swim approx. twice as quickly as with bi-fins, but you burn twice as much oxygen as with bi-fins ;

the monofin eliminated completely the bi-fins in finswimming because in this sport "efficiency" means speed... in apnea, it is not so obvious precisely because speed is not the target...
cjborgert said:
and long blades can increase your speed more rapidly than other fins . . .by displacing more water with each kick. . .
in your post you talked about the GEOMETRICAL DIMENSIONS of the fins but you forgot extremely important parameters : the STIFFNESS (static, dynamic or "response") and the MECHANICAL properties....

you forgot to talk about ENERGY spent with each kick....
 

Panos Lianos

New Member
Oct 31, 2004
163
25
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You should be able to go further with fins than without. If this is not the case, then you are doing something wrong, probably your technique.

One other thing you should consider is the right speed. This is totally up to you to find out by experimenting. I have done more that 140m in dynamic both going fast and relatively slow, so you should try to find the right pace FOR YOU. The faster you go, the harder it gets to maintain a good technique, because of the extra work your legs have to do and so you tend to bend your knee when you go fast. Your legs should remain straight with the movement being from the hip (the top of your leg).

A stiff fin will allow you to go faster but will NOT help you correct your technique. To some of my students, I tell them to use short fins for a few sessions, in order to learn the proper technique first and then move to a “pure” freediving fin. It is easier to use them right once you actually KNOW what you are supposed to do. Finding the right technique is a difficult task and can only be done when you get feedback from an experienced instructor. I use an underwater video to show my students what they do wrong and eventually they get much better, much faster than without the video.

Blades: I always like blades that are on the “soft” side, rather than the “stiff” side. They are much easier to use and help you use the right technique. You don’t want them too soft (cause they are not so efficient) but not too hard either (cause they are hard on your legs and will tire you up very soon). Pure carbon blades are the more efficient because of the properties of the material but stiffness depends on the individual. Most spearfishers tend to go for stiff blades because they THINK they will take them deeper. That’s why their technique is so bad :)

Hope I’ve helped a little.
 

SanSan

New Member
Apr 22, 2005
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Re: Don't Kick Harder!

subaquaticus said:
"efficiency" can be an ambiguous word and requires to be defined... it depends on the goal...

in static apnea "efficiency" is the time you spent underwater...

in dynamic apnea "efficiency" is the length you swim underwater (and not the time)

Well I wouldn't totaly agree on Ur definition of efficiency. I would define it more like amount of oxygen spent per second, minute or meter (depends on the goal). What U wrote is the goal itself. If I take ur definition that means that somebody thats making, lets say 5 min statics is absolutely more efficient than somebody thats makin 4min. But that if the one making 5 min has 50% greater lung. What if the one making 4 min had some reserve and could make 2 more minutes. I wouldn't say the one making 5min is being more efficient.
If u define efficiency like: Xo2/min u can calculate ur goal if u have the amount of o2 u have and will spent. U get the equasion:

available O2 : efficiency (xo2/min)

As for time not being important in dynamics i wouldn't agree either. Sure it isn't the goal but in time spent under water you also burn oxygen eaven when not moving. The more if u where swimming before...
 

firefly

New Member
Mar 2, 2005
21
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many thanks for all the replies

i think i do get a better picture now.

i did try in the pool to swim fast and slow and i agree that swimming faster is more demanding. also i did notice that it was more difficult to maintain good kicking technique (good by my beginner standards ;) ).

also my cressi fins are the grey ones. they are not so stiff as the black ones from what i was told. i feel quite alright with the stiffness of the blade.

i find it amazing that stefane misud can swim so far so slowly. i bet he must be very relaxed then. if a diver is swimming fast in dynamics how important is relaxation then?

greetings from sandra
 
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